/// <summary>
/// Blocks until the specified number of tokens are available for consumption
/// and then consumes that number of tokens.
/// </summary>
/// <param name="tokens">The number of tokens to consume</param>
/// <param name="timeout">The maximum amount of time, in milliseconds, to block. An exception is
/// throw in the event it takes longer than the stated timeout to consume the requested number
/// of tokens</param>
public void Consume(long tokens, long timeout = Timeout.Infinite)
{
if (timeout < Timeout.Infinite)
{
throw new ArgumentOutOfRangeException(nameof(timeout),
"Invalid timeout. Use -1 for no timeout, 0 for immediate timeout and a positive number " +
"of milliseconds to indicate a timeout. All other values are out of range."
);
}
var startTime = _timeProvider.GetUtcNow();
while (true)
{
if (TryConsume(tokens))
{
break;
}
if (timeout != Timeout.Infinite)
{
// determine if the requested timeout has elapsed
var currentTime = _timeProvider.GetUtcNow();
var elapsedMilliseconds = (currentTime - startTime).TotalMilliseconds;
if (elapsedMilliseconds > timeout)
{
throw new TimeoutException("The operation timed out while waiting for the rate limit to be lifted.");
}
}
_sleep.Sleep();
}
}
/// <summary>
/// Consumes multiple tokens from the bucket. If enough tokens are not currently available then this method will block
/// </summary>
/// <param name="numTokens">The number of tokens to consume from the bucket, must be a positive number.</param>
public void Consume(long numTokens)
{
while (true)
{
if (TryConsume(numTokens))
{
break;
}
_sleepStrategy.Sleep();
}
}
/// <summary>
/// Consume multiple tokens from the bucket asynchronously. This method does not block
/// <param name="numTokens">The number of tokens to consume from the bucket, must be a positive number.</param>
/// <returns>A task that returns once the requested tokens have been consumed</returns>
/// </summary>
public async Task Consume(long numTokens, CancellationToken cancellationToken = default(CancellationToken))
{
while (true)
{
if (await TryConsume(numTokens).ConfigureAwait(false))
{
break;
}
await _sleepStrategy.Sleep(cancellationToken).ConfigureAwait(false);
cancellationToken.ThrowIfCancellationRequested();
}
}
